摘要:
A crank-type non-beam pumping unit, including a belt, a foundation, a crown sheave, a frame, a support rod, a belt pulley, a pin shaft, a crank, a transmission shaft, and a bracket. The bottom of the frame is disposed on the foundation, and the top of the frame is supported by the support rod. The top of the support rod is hinge connected to the frame, and the bottom of the support rod is hinge connected to the foundation. The bracket is disposed on the foundation, the transmission shaft is disposed on the bracket, and the crank is disposed on the transmission shaft. The crank rotates synchronously with the transmission shaft, and the belt pulley is disposed on one end of the crank via the pin shaft. One end of the belt bypasses the crown sheave, and is connected to a smooth sucker rod.
摘要:
The method for preparation of polyisoprene includes conducting polymerization reaction of isoprene in a first organic solvent under the presence of rare earth catalyst I and rare earth catalyst II, to obtain polyisoprene with bimodal molecular weight distribution, wherein the polymerization reaction conditions are controlled to ensure the peak molecular weight of the high molecular weight component fraction in the polyisoprene is 1×106-2×106 and the peak molecular weight of the low molecular weight component fraction is 2×105-4×105, and the weight ratio of content of the high molecular weight component fraction to the low molecular weight component fraction is 1-25:1. The molecular weight distribution of the polyisoprene obtained with the method provided is bimodal distribution; therefore, the polyisoprene not only has the mechanical properties of polyisoprene with high molecular weight, but also has the processability of polyisoprene with low molecular weight.
摘要:
This invention relates to a tubular cracking furnace, especially an ethylene cracking furnace, which comprises a convection section and a or dual radiant section(s), at least one heat transfer intensifying member arranged in at least one pass each radiant tube in said radiant section, said at least one heat transfer intensifying member comprises a first heat transfer intensifying member, which is arranged at a location between 10D and 25D upstream of the extreme point of said at least one pass radiant tube metal temperature, wherein D is the inner diameter of the radiant tube having heat transfer intensifying members. The present invention could achieve the best enhanced heat transfer result with given number of heat transfer intensifying member, by optimizing the locations of heat transfer intensifying members in the radiant tube.
摘要:
A catalyst component for olefin polymerization includes magnesium, titanium, a halogen, an internal electron donor compound, and a precipitation aid. The precipitation aid includes a precipitation aid represented by general formula (I). The precipitation aid represented by general formula (I) includes isomers represented by general formula (I-a) and/or (I-b).
摘要:
A microspheric ionomer having a cross-linked structure, a preparation method therefor, applications thereof, and a preparation system thereof. The ionomer comprises structure units A represented by formula (1), structure units B represented by formula (2), and a cross-linking structure provided by a cross-linking agent, M being separately selected from H, a metal cation, and a straight chain, a saturated alkyl of branched or ring-shaped C1-C20, R being H or a methyl; and metal cations are introduced to part of structure units A in the ionomer. The ionomer shows an outstanding effect on nucleation of PET, serves as a nucleating agent for PET modification, so as to obtain a corresponding PET composition. A system and method for continuously preparing maleic acid ester ionomer microspheres and cross-linked maleic acid ionomer microspheres, so as to achieve continuous preparation, washing and separation of ionomer microspheres, effectively stabilizes the separation effect, and avoids frequent start and stop operations of a centrifuge.
摘要:
A lanthanum oxycarbonate catalyst, and a preparation method therefor and an application thereof are provided. The lanthanum oxycarbonate catalyst contains a rod-shaped lanthanum oxycarbonate catalyst and a nearly parallelogram lanthanum oxycarbonate catalyst. The lanthanum oxycarbonate catalyst can be used for efficiently performing a methane oxidative coupling reaction at a relatively low temperature.
摘要:
The invention belongs to the field of olefin polymerization and relates to a propylene-based copolymer, its preparation process and use, and a polypropylene composition thereof. The propylene-based copolymer can contain 60-95 wt % of propylene-derived structural units and 5-40 wt % of comonomer-derived structural units; the propylene-based copolymer has a comonomer dispersion degree D[PCP]/[C] in the range of 50%-70%, wherein the comonomer dispersion degree D[PCP]/[C]=[PCP]/[C]×100%. Upon blending the propylene-based copolymer of the present invention with a polypropylene, the copolymer has excellent compatibility with polypropylene, and can promote the crystallization of the polypropylene and can improve the mechanical properties of the resulting polypropylene material.
摘要:
The present invention relates to the field of fluid heat transfer, and discloses a heat transfer enhancement pipe as well as a cracking furnace and an atmospheric and vacuum heating furnace including the same. The heat transfer enhancement pipe (1) includes a pipe body (10) of tubular shape having an inlet (100) for entering of a fluid and an outlet (101) for said fluid to flow out; internal wall of the pipe body (10) is provided with a fin (11) protruding towards interior of the pipe body (10), the fin (11) spirally extends in an axial direction of the pipe body (10), wherein a height of the fin (11) gradually increases from one end in at least a part extension of the fin. The heat transfer enhancement pipe can reduce thermal stress of itself, thereby increasing service life of the heat transfer enhancement pipe.
摘要:
A grafted polypropylene resin is prepared by a grafting reaction of a polar monomer capable of absorbing microwave so as to raise its temperature in a microwave field to more than 200° C. and a solid polypropylene resin using microwave irradiation without adding an initiator. The polar grafted polypropylene resin that does not contain initiator residues and does not have a significant reduction in molecular mass compared with a resin before grafting is obtained.
摘要:
A magnesium-based solid, by means of determination based on a nitrogen adsorption method, has a multimodal pore distribution and a specific surface area of not less than 50 m2/g, and the pore size distribution of the solid is in a range of 1 nm to 300 nm. There is at least one peak within a pore size range of less than 10 nm, and there is at least another peak within a pore size range of not less than 10 nm. A catalyst is formed using the solid catalyst component is used for propylene polymerization.